Effects of micro-Opioid Receptor Gene Polymorphism on Postoperative Nausea and Vomiting in Patients Undergoing General Anesthesia with Remifentanil: Double Blinded Randomized Trial

Association between postoperative nausea and vomiting (PONV) and micro-opioid receptor A118G single nucleotide polymorphism (SNP) is undefined and might underlie inconsistent results of studies on PONV occurrence in patients undergoing general anesthesia with the opioid, remifentanil. Four hundred and sixteen Korean women undergoing breast surgery with general anesthesia were randomized to receive remifentanil 10 ng/mL (plasma-site, Minto model) using a target-controlled infusion device and either propofol for total intravenous anesthesia (T group) or sevoflurane for inhalation anesthesia (I group) with bispectral index values maintained between 40 and 60. Blood specimens were collected after anesthesia induction for A118G SNP analysis. PONV and postoperative pain were evaluated. A118G SNP type distribution among Korean female adults studied was AG (n=195)>AA (n=158)>GG (n=63). Regardless of anesthetic technique, patients with GG types had lower PONV scale on arrival at postoperative care unit (PACU) (P=0.002), while T group showed lower PONV scale than I group up to 6 hr after PACU discharge in AA and AG types. No differences were apparent for postoperative pain among opioid receptor polymorphism. PONV occurrence differs according to opioid receptor polymorphism and anesthetic technique in patients undergoing general anesthesia with remifentanil.

Correlation of circulatory immunoglobulin levels with Mu opiate receptor allele.

Opiates are known to induce immunosuppression in their users (addicts). Evidences supporting their role in suppressing a variety of immunological end points in addicts have been reported by several investigators. In the present study, we investigated the changes in serum immunoglobulin (Ig) levels and their correlation with Mu opiate receptor (MOR) genotypes. Eighty-seven users and forty-five non-users were recruited for the study. Genomic DNA, isolated from the peripheral blood, was used for genotyping for C17T and A118G polymorphism using PCR-RFLP method. The frequency of A and G alleles in non-users was 89% and 11% respectively, whereas in addicts, it was 67% and 33% respectively. Case control analysis between groups revealed that 118G allele was associated with opioid dependence [Chi square (chi2) = 13.56, odds ratio (OR) = 3.90, confidence interval 95% (CI 95%) = 1.80-8.67, p = 0.000231]. C17T polymorphism showed no association with opioid dependence [(chi2) = 0.9, OR = 2.49, CI 95% = 0.528-16.12, p = 0.343]. Mean Ig levels, both IgG (student's t-test = 2.2738, p = 0.007) and IgA (student's t-test = 2.848, p = 0.0051) differed between opiate users and nonusers. IgG and IgA levels were also significantly different in individuals with different MOR genotypes. Immunosuppression was observed in AA genotype-bearing individuals, while no suppression was seen in AG and GG genotypes bearing individuals. In case of C17T polymorphism, both CC and CT genotypes bearing individuals showed immunosuppression, as judged by circulating Ig levels.

Pharmacotherapy for Alcohol Dependence: Anticraving Medications for Relapse Prevention

Alcohol dependence is a chronic disorder that results from a variety of genetic, psychosocial, and environmental factors. Relapse prevention for alcohol dependence has traditionally involved psychosocial and psychotherapeutic interventions. Pharmacotherapy, however, in conjunction with behavioral therapy, is generating interest as another modality to prevent relapse and enhance abstinence. Naltrexone and acamprosate are at the forefront of the currently available pharmacological options. Naltrexone is an opioid receptor antagonist and is thought to reduce the rewarding effect of alcohol. Acamprosate normalizes the dysregulation of N-methyl-D-aspartate (NMDA)-mediated glutamatergic excitation that occurs in alcohol withdrawal and early abstinence.These different mechanisms of action and different target neurotransmitter systems may endow the two drugs with efficacy for different aspects of alcohol use behavior. Since not all patients seem to benefit from naltrexone and acamprosate, there are ongoing efforts to improve the treatment outcomes by examining the advantages of combined pharmacotherapy and exploring the variables that might predict the response of the medications. In addition, novel medications are being investigated to assess their efficacy in preventing relapse and increasing abstinence.